| PublishDate | 2017-01 | http://fasb.org/us-gaap/role/tin/value |
| Positive_XBRL_Value | Increase | http://fasb.org/us-gaap/role/tin/value |
| Negative_XBRL_Value | Decrease | http://fasb.org/us-gaap/role/tin/value |
| Note | Element is modeled from perspective of statement of financial position. | http://fasb.org/us-gaap/role/tin/usage |
| PublishDate | 2017-01 | http://fasb.org/us-gaap/role/tin/usage |
| PublishDate | 2017-01 | http://fasb.org/us-gaap/role/tin/resource |
| Source | Taxonomy Implementation Guide | http://fasb.org/us-gaap/role/tin/resource |
| SourceName | Retirement Benefits-Phase 1 | http://fasb.org/us-gaap/role/tin/resource |
| pdfURI | https://www.fasb.org/retirementbenefitsphase1_2017 | http://fasb.org/us-gaap/role/tin/resource |
| elementCreationTaxonomyVersion | 2012 | http://fasb.org/us-gaap/role/tin/taxonomyImplementationNote |